DOI

10.5703/1288284313359

Abstract

The increased demand on the current highway system has caused transportation agencies to increase scheduling for nighttime work in order to alleviate daytime work zone congestion, especially during peak traffic hours. Although traffic congestion is reduced, safety in nighttime workzones remains a concern among both transportation agencies and contractors. According to the Federal Highway Administration (FHWA), approximately one-half of the fatalities that occurred in workzones nationwide occurred at night. These work zone statistics have received increased attention among agencies to evaluate planning and safety issues concerning the workers and the general public on nighttime workzones. Four separate, but interrelated research studies were conducted between September 2005 - May 2007 to address safety issues in nighttime construction and maintenance projects on highways in Indiana. The first study investigated owner and contractor safety management planning for nighttime construction and maintenance operations, while the second study investigated traffic control planning and implementation procedures for nighttime construction and maintenance operations. The third study investigated the effectiveness of speed control measures on nighttime construction and maintenance projects and the fourth study evaluated the effectiveness of high-visibility personal protective equipment practices. The safety management practices of the general contractor heavily influence the perception of safety of nighttime construction workers. Workers and general contractors have similar perceptions about the strategies necessary to improve safety on the nighttime construction jobsite. Frequently, the safety threat presented by the general public is cited by nighttime construction and maintenance workers as making them feel unsafe on the jobsite. Methods to raise the awareness of the general public about nighttime construction are needed in order to improve the safety of the nighttime construction and maintenance workers from the dangers imposed by the general public. Traffic control planning by highway agencies and contractors impact the supervisors’ and the workers’ perceptions of safety. The results from the formal interviews with Indiana contractors and Indiana Department of Transportation (INDOT) personnel indicated that contractors are becoming more involved in traffic control planning. Increased law enforcement and public awareness were among the most important traffic control strategies for improved nighttime safety indicated by the supervisors and the workers. The presence of police enforcement, a high percentage of semi trucks in the traffic, and a high flow rate – all reduced mean speed through nighttime workzones Changeable message signs, while more expensive than work zone speed limit signs, are already being used on many nighttime workzones but were not found to affect mean speeds. Police enforcement was found to reduce mean speeds, was the most expensive method of speed control in the study. The safety garment currently used by the workers of the Indiana Department of Transportation is a yellow-green safety vest with a four-inch wide fluorescent orange strip with two one-inch strips of reflective silver material. The visibility of the safety vest currently used by INDOT can be increased by adding a secondary high-visibility PPE such as safety pants and/or retroreflective bands. Current safety training in personal protective equipment (PPE) is focused on which PPE is applicable for a certain type of job and how to use the PPE. However, training workers how to maintain the PPE will increase its useful life, resulting in savings for the owner and/or the general contractor. In order to improve the visibility of current PPE garments there should be differences in the values of retroreflectivity between the primary and secondary high-visibility PPE and larger variance in the retroreflectivity values across the garment. In addition, the garments should be changed or rotated with other garments periodically to ensure that the attention of drivers is being captured.